Dephasing due to Spin–Wave Excitations in Ferromagnetic Metals

Abstract

The dephasing due to spin–wave excitations is studied for ferromagnetic wires of mesoscopic dimensions in the diffusive regime. The spin–wave dephasing time τ_φ for conduction electrons is calculated as a function of temperature T on the basis of the s–d interaction model. It is shown that in the absence of an external magnetic field, the spin–wave dephasing in some cases becomes comparable to, or even dominates, the ordinary dephasing due to Coulomb interactions. It is also shown that if a magnetic field H is applied parallel to the wire, the spin–wave dephasing is exponentially suppressed with the increase of H at the low-temperature regime of γH>>T (γ: gyromagnetic ratio). This strong H-dependence can be used to examine the influence of the spin–wave dephasing on quantum interference corrections.